1. Field of the Invention
This invention relates to signage systems for the display of advertising material and especially to such systems of the fixed billboard type having removable elements.
2. Discussion of Related Art
Conventional billboards with removable panels have their panels attached in a normally fixed relation to a rigid backing frame, with each panel being attached separately by a conventional means, such as screws, nails, dowels, and/or pins. Removal of these panels requires much time and, because of the precision of fastener locations, requires special fabrication of board elements. Also, because signage systems are usually elevated 10 feet or higher above the ground, they customarily have a narrow walkway several feet wide affixed below the sign itself in front of each viewing area to accommodate the installation of advertising material and removal of same.
U.S. Pat. No. 2,775,834, issued Jan. 1, 1957, to Miller, shows a display device comprising a support member disposed at a site suitable for the display of advertising media. A sheet of paper-like material bearing advertising media on one side and adhesive on the other side is removably attached to the display device. U.S. Pat. No. 2,260,658, issued Oct. 28, 1941, to Connors, shows a signboard having an elongated base casing connected to a frame. A pair of top and bottom grooves extend along the frame and a plurality of advertising display panels fit loosely in the grooves side-by-side for sliding into different positions in the frame. The lower edges of the panels can be removed from the grooves by way of a gap provided in the bottom frame. U.S. Pat. No. 2,948,976, issued Aug. 16, 1960, to Miller, discloses a lightweight panel assembly for use with billboards. Each panel comprises a rigid framework having a plurality of vertical and horizontal cross frame members defining a lattice separated by a number of open areas. Lightweight metallic material is rigidly affixed to the framework and covers the open areas. Each of the frame members has an elongated continuous integral retaining lip formed thereon whereby the metallic material is positively supported on each side and held in a taut rigid condition.